Automatic table-lowering attachment



R. T. HAZELTON.

AUTOMAHC TABLE LOWERiNG ATTACHMENT.

APPLiCATION FILED MAYH, 19H}.

Fatmfled Nov. 15 1921.

6 SHEETS-SHEET L amom/ho a R. T. HAZELTON.

A UTOMATiC TABLE LOWERiNG AT%':: .E;HMENT.

APPLiCATlON FILEDIMAY 11, 2-515.

1,397,210., Emma Nov 15,1921,

6 SHEETS-SHEET 2.

R. T. HAZELTON.

AUTOMATIC TABLE L'OWEFHNG ATTACHMENT. APPLICATION FlLED MA-YH,1915.

1397,21 PAAAAAAA N0v.15,1921.

6 SHEET$-SHEET 3.

R. T. HAZELTON.

AUTOMATiC TABLE wwzmma ATTACHMENT.

I APPLICATION FILED MAY 11. 1915.

1,397fi1 Q Patented Nov. 15, 192R 5 SHEETS SHEET 4:

K g mg R. T. HAZELTON. v AUTOMATiC TABLE LOWERING ATTACHMENT.

APPLICATION FILED MAYH, I915. l ,89K81U Patented Nov. 15, 1921.

6 SHEETS-SHEET 5.

TON.

T. HAZEL AUTOM T BLE LOWER ICATION FILED M ING ATTACHMENT.

AYH, 191s.

Patented N0 I 1921'. l' 6 SHEET HEET 6.

I I v "I. 0 I

3} 3 )Z 21 Specification of Letters Patent.

Patented Nov. 15,1921.

Application filed 11, 1915. Serial No. 27,323.

To all t l/10m it may con cern Be it known that l, iiionnirr T.HiiznLToN, a citizen of the United States and residing at Cincinnati, inthe county of Hamilton and State of Ohio, hare invented a new and provedAutomatic 'l able-Lowering Attachment, oi which the followingspecification is a hill disclosure.

his invention deals With feed mechanisms for regulating the cha ac-tier;extent and. duration of the cutting action oi a tool with respect. tothe \vorle and it proposes antimprovement whereby certainoperations maybe conducted automatically that have here toloro been performedn'ianually. In rarious tool mierations it has been customary to proridchcertain amount of relief for the tool with relation to the work during;the return stroke so as to prevent the tool from mann ngth appearance oithe already machined surface. This action has been ac compiishedautoratically in various ways, but in the greater nun'iber ol instanceshas been the tool holder that was retracted during the return strokerather than the taolior work support. and this has been a mere matter ofselection d ictated by matters of general ronu-niencc and expediencyrather than because of any lacl-I of designing shill on the part of theconstructor. That is to say, in the greater number of instances the di"gner has preferred to provide the tool holder with the automaticretracting features on account of its lightness and lack of momentum,whereas the table, or work holder, has ordinarily be i a relativelyheavy ing features has been centered largely in connectionwith machinesusing; tools such as those employed in lathes, and in these machines, I.shavers. pianers etc. theri has been a substantial reason for the use ofsuch retracting :teaturcs. in the case of machines using rotary cutterssuch as milling machines there is ordinarily necessitated no especialnecessity for automatic retract ing features, but the herein disclosedmechanism has been chosen in order to satisfy the demand for a machinetool that Will embody automatic retracting features so as to produce asuperior finish on the article. In milling machines itis obviouslybetter practies to provide the table with the retracting features ratherthan the spindle; because from a mechanical standpoint it, is ratherawkward to lift the spindle during the return strolce of the workalthough this, of course can be done at the sacrifice of an increase inthe manufacturing cost of the machine tool. 7 l

Now the herein disclosed mechanism has, therefore, been designed so astoprovide the work support. w th means for automatically retracting or\vithiilrawing the Work from the cutter during the return stroke of thetable, and in embodying this broad principle special effort has beenmade to create a very simple, durable and effective way of achieving theautomatic retraction.

This invention, therefore, endeavors more especially to create a fewpart organization which may be applied to tiny existing table withoutdisturbing the usual automatic feeding means preferred, and which williause the table to be automatically raised into a cutting positionduring the torvvard stroke of the Work and automatically lowered toclear the cutter during the return stroke of the Work. Another is todesign an exceedingly simple table retracting means in which all of theparts and elements Will be rugged, capable of being easily made andeffective to operate efficiently and durably in connection with millingmachines of any existing construction and Without requiring elaboratechanges in the arrangement thereof.

Other objects will be in part, obvious from the annexed drawings and inpart indicated in connection therewith by the following analysis of thisinvention.

This invention accordingly consists in the features of construction,combination of parts and in the unique relations of the members and inthe relative proportioning and disposition thereof; all as morecompletely outlined herein.

To enable others skilled in the art so fully to comprehend theunderlying features thereof that they may embody the same by thenumerous modifications in structure and its relation contemplated bythis invention, drawings depicting a preferred form have been annexed asa part of this disclosure, and in such drawings, like characters ofreference denote corresponding parts throughout of the table showing theaccessibility of certion of the,'machine. Fig. 5 is an enlarged,

tain of the control-features Fig. 2 is a left hand side elevation of themachine shown by Fig. 1. Fig. 3 is a rear elevation of said machine.Fig. 4 is a right-hand side elevafragmentary elevation partially insection of the front lopgitudiual edge of the table showing onearrangei'nent of operating dogs'and certain details of thetripunechanism acturated thereby. Fig. 6 is a fragmentary planmechanisms.

partly in section of the construction shown in Fig. 5. Fig. 7 an endelevation partly in section through line 7-7 of Fig. 5 showing furtherdetails of the trip and control- F ig. 8 is a section through line 88 ofFig. 7 showing further details of said mechanisms. Fig. l) is a sectionthrough line 9- 9 of Fig. 8. Fig. 10 is a sectional plan through line10-10 of Fig. 7. Fig. 11 is a sectional plan through line. 11-41 of Fig.7. Fig. l2.diagrammatically represents a succession of phases of one ofthe cyclesavailable for a stroke oi the table. Fig. 13 representsanother succession of phases (EOIiStltlltlllg another cycle of thetable. Fig. 145 is aside elevation 01 a table embodying thisconstruction, Fig. 15 is a section through line 15-l5 of Fig. 14. Fig.16 is a section. through line l6'l(i of Fig. 14.

Continuing, now by way of a more detailed description, it may at theoutset be stated that this invention contemplates relatively movabletool and work-supporting elements, 'suclras the spindle and table of amillingmachine, on one oi which are adjustably mounted a plurality ofstops or dogs which 'cotiperatcwith means instrumental in deter miningthe rate at which the spindlcshall travel. relatively to the table. Itis to be particularly noted that from a mechanical standpoint it is thesame thing whether the tool-carrier is actually reciprocated during "thecutting operation and the table held stationary, or conversely, sincethe matter is merely one of relative movements. In this embodiment, aseries of dogs is so constructed and related to a trip means that onedog may cause the tableto execute a quick traverse, the next dog maycause it to feed, the next again to quick-traverse. the next again tofeedand the last to return at a quick-traverse rate. To obtain anadequate understanding of this invention, it should be kept in mind thate term feed as used herein, indicates any one of a sense of reiativciythe rate at which the table thus feeds and,

when so used they are to be understood as i not including the mechanismdetermining the speed of rotation of: the cutter-spindle. So also, theterm quick traverse is indicative of the rapid non-tooling movementwhereby the table travels over blank spaces; which movement usuallyrepresents the maximum speed at which the table may move and abruptlyreverse, stop or moderate to a feed without undue shock to he parts. Itis desirable that this fast rate or quicktraverse be the maximum ratepermitted by the construction of the table, for the sake of efiiciency,and that it be unaffected by changing in the slow speed or feed ot thetable, such as may be resorted to to meet difi'erent tooling conditions.I

Before outlining the specific features of construction whereby thesefunctions are obtained, it will be convenient first to describe certainmain elements of a conventional milling machine. These comprise a tablethat supports the work and which is reciprocatcd to and from to subjectthe work bolted thereon to the effect of the cutter that is secured toampindle which is continuously rotated by power derived from the samesource or prime mover that actuates the table. in order to enable themachine properly to cxccutc its functions, these actuated elements mustbe capable of being brought into adjusiable relation with one another innot less than two directions. This is accomplishcd by an interpoiientframe-unit that iiucrrcncs betwccn the frame-unit C that dirccilysupports the spindle and the frameunii that directly mounts the table.In the type of machine here illustrated, the frame-unit A that carriesthe weight of the table also constitutes the base or bed of the machine.but, it 'will be obvious that any one ol' thc frau1e-units may be usedas the bed of the machine. The spindle-mounting frame-unit is herecarried directly by the intci-ponent frame-unit B which here restsdirectly on the bed and upriscs therefrom in the form of a standard orhead. The chief mechanical cluiracteristic of the intcrponent frame-unitB is that it provides a vertical adjustment as to the spindle-mountingunit (7, 0., making them mutually adjustable, i. (1.. transversely toone another.

The bed A consists of a heavy frame providing guide-ways 1 and 2 in itsupper surface for positioning the head and tail-stock oi the tool. Thisbed is supported on legs 3 and it rises from a pan 4 that is adaptedsame into an oil' well S hereinthefOrm of a box cast magi-n1 with theand the pan *1 ma mannerniore clearly shown by the drawings. @Alcl ting6 forming a cover plate and a housing 1 or the operative features isbolted to'th'e hon and it pro-,

vides a part"? that journals thepropelling shaft of the pump. A pipe 8extends through this topcasting 6 and receives the oil delivered bythepump and conveys it to certain 'wearlng surfaces of the machine,

as will be hereinafter more fully outlined;

For the purpose ofjjcatching res dues dripping from the overhangingportions of the table, chutes 9 and lOma'y project laterally from thepan 4 and in-eferably are detach-.

ably mounted on the same'by means of lugs 11 extending from their'undersides and receiving the edges of the pan 4...

The head B consists of a main casting 12 the bottom of which is finishedto intertit with the slideways l-and 2 of the bed, and

this head is adjustable along said slide ways, and to enable it to bemoved "conven iently, a screw 123 is keyed to the casting 12 andprojects through a nut 1 j'ournaled in a bracket 15 extending from thebed. This nut 1 1 is in turnahtated by a hand wheel 16 to enable theextent of movementaccurately to be determined.v IA peripheral part 17 onthebracket eoiipe'rates with a member 18 rotatable with the nutand by.

means of graduations; on these respective elements, the extent ofrotation may be accurately determined. The part 18 is preferably.journaled on the wheel supporting shank'piece 19 and is ,capable ofbeing temporarily fixed in; any desired position by means of athumb-screwQO-jsothat'the zero setting of the graduations maybearbjitrarily made? at a-nyposition of the, casting V '12 von the bed,To enable the head to be locked on the bed, one or more T-bolts and nuts21 pass through holes in a flange 22 of the head andflcooperate with theunderlying slots of the guide vays 1 and 2, and thus enable the casting/to be drawn tightly onto the bed. u

'Extending atone side of the casting 12 are. two walls 23,,"which,together: with an .end wall 2a form a pocket ford gaining oil,

and also forn bearingsfo'r th edrii ing pulley shaft 25. Tlns shaftisiyournaled at one end in the inside-wall 23.111111 its other endprojects through. the outside wall and sup ports certain means fortrai'islnitting motion to the spindle, aswill be hereinafter described.Keyed to the shaft 25 is a driving pulley 26, and loosclymountedconcentrically with said'shaft is a loose pulley 27.

Slidably mounted ona shaft 28 supported by the walls 23 is a. beltshifting fork 29 which is reciprocated by a handle 30 at the end of alever pivoted at 31 to the main 65 head casting and having an operatingarm I slight sprin outer. end. I an ntermediate gear 58 that is mountedon a .32 terminating in a slotted end 33 receiving from the shaft 25 isa tubular bracket 35 in the lower end of which is journaled a shaft 36which is driven by the sprocket chain 37 riding from sprocket 38 on thepulley shaft 25, and sprocket 39 on the shaft 36, which conveys thepower for feeding the table and also provides for the operation of theoil pump. This latter is accomplished by'means of a pulley 40 mounted onits end, which cooperates with a corresponding pulley 41 on the drivingshaft of the pump. A casing 4-2 is bolted to the bed and incloses thebelt and pulleys, and it is to be noted that the sprocket 39 is splinedto the shaft 86 so as to permit of bodily movement of the bracket andits contained. elements axially of the shaft 36.

The spindle carrier C consists of, a block in which is journaled thespindle, and which .is slidably adjustable on the head B in. a

ing faces 19 and are also provided by the legs in and L4 and the innerpair 49 cooperate with similar bearing faces on the head 51 of thespindle carrier C. A pressure member- 52 is slidably mounted on a stud(not shown) extei'iding rearwardly from the spindle carrier C and aclamp nut screw-threaded to said stud enables the clanipinp member 52 tobe forced toward the elongated head 51. By reason of a in the legs 43and 44 of'tlie hcad'castingl3, all of the bearing surfaces are broughtinto tight binding relation and a most rigid mounting is provided.

The spindle support 0 is apertured and a suitable spindle 56 isjournaledin the same and is driven by a gear 57 keyed to its This gear in turnmeshes with stud 59 carried by an arm (i fpivoted to a part (31concentric with the pulley shaft .25. A link ui'l'maintains coincidenceof thepitch lines between the gears 57 and 58, and the latter is fast toa gear Gel that is maintained in proper pitch relation with a pinion bymeans of the arm 60, as will be understood. A housing (36 is secured tothe arm 60 and protects the gears, and for the purpose of more rigidlysupporting it after the parts have been adjusted it is provided with an.extension 6? having a slot receiving a bolt 68 extending from thesupport and which may be tightened up to secure all of said partsrigidly together.

It will be perceived that the organization of the head thus fardescribed permits of any desired adjustment of the spindle. and at thesame time maintains a positive direct drive for the same in all of itspositions and also enables the same to be most rigidly clamped in any ofits positions. The means for moving the spindle su port consists ofascrew pinned to the support and extending vertically through a nutmounted in a cross-yoke 71 and turned by means of a hand-wheel 72. Thiswheel provides an adjustable collar T3 witl a lug screw T1 for enablingmicrometer adjustments to be obtained in the manner recited inconnection with the hand-wheel 16.

It is noteworthy that the power control hand 30 for shifting the drivingbelt as well as the handle T2 for the vertical adjustment ot the spindlecarrier. vand also the hand wheel ltl for ellcctiug a transversemovement of the head on the bed which is accessible to the operator atthe front of the machine, that is. at. the. same side of the. machineproviding handles for controlling the movements of the table. Themounting and arrangement of this plate may now be descrilaal. a

The table I) as here shown is elongated and adapted to reciprocatetransverselyto the bed. it being slidably mounted thereon by means ofsuitable.guide-ways 71. said table having counterpart guide-ways T5 inits under face. fced-screwv it) is journaled at its ends in said table,and the front end 7T 01" the feed screw projects slightly and iscontoured to receive an operating handle or wheel to permit of handactuation should that be desired. Extending along one side of this tableare two slots TS-T0 located in different planes and which adjustablycarry dogs -81-82 and 83 which automatically actuate control levers 84and 85 uprising from a speed change box E that is arranged at the frontside of the bed A um'lerneath the table D. and which receives power bymeans of a shaft 80 extending transversely through the bed parallel withthe table and geared at its rear-end to the shaft 30 previouslydescribed. v

The foregoing organization will be complete for many classes of work,but to satisfy other requirements the bed A may extend beyond thetripping side of the table D, and on the same may be mounted a head andspindle organization duplicating that already described, or a tail stockfor supporting an arbor may be used according to the followingconstruction.

The tail stock F consists of a bifurcated casting having an interfittingrelation With grooves in the bed and adapted to be held in place bymeans of bolts 87 in a way simijournaled within the casing, and is indriv-- ing connection with the main source of power of the machinethroughout the elements illustrated. The feed-screw shaft 76 is suitablyjournaled at each end of the carriage or table D and it is translatabletherewith and ')rojects through the casing I.

A nut 107 is journaled within, the bearing sleeves 108 and 109 that aresuitably fixed within boxes formed in the tasing E. In

this instance, the nut 107 is of elongated form andonly a portionthereof is provided with. the screw-threads 110, which engage with thethreads of the screw-feed shaft 76.

By this construction, the nut 107 is given a considerable bearingsurface; which is always an important consideration in supporting therotating elements of a machine tool, as it tends to prevent vibration orchatter. and to prolong the life of the machine.

A clutch-collar 111 is splined upon the shaft 86 and is provided withclutch-teeth 112 adapted to be engaged with the clutchteeth 113 formedon the sleeve 114, which in turn is loosely supported upon the drivingshaft 86. car 115 is splined upon the sleeve 114 and is adapted to beslid thereon to enable the gear 115 to be engaged with any one of thegears 116, 117, 118 and 119, fixed upon the nut- 107 to impart any oneof a variety of speeds to the nut.

As illustrated, the gears 116, 117,118 and 119 are of the sainediameter, but each has a different number of teeth. This will give theresults (when this system is employed) desired for a feeding mechanism;and it has the advantage of enabling the gear to be shifted laterallyinto direct engagement with any one of the gears of the series withoutusing compllcated tumblers. By the form herein illustrated, there isproduced a simple and compact arrangement, with very few parts, but itis obvious that other systems of speed-change gearing can be employedbetween the nut and driving shaft to produce equal results.

The gear 115 is provided with a hub extension 120 having an annulargroove 121, into which the arm 122' of the shiftingmechanism engages.The arm. 122 is fixed to a rock-shaft 123, journaled within a bearingformed in the casing E, and projecting through the same, and 124represents a hand nae lever fixed to the roclcshaft, with its oppo siteend provided with a detent mechanism 125 for locking the handle, gearand shifting mechanism in any adjusted position.

A gear 1:26 is fixed to the teed-shalt 86 in mesh with a gear 12?loosely journaled withinthe hearing sleeve 12S fixed within the frame E,with the screw projected through the bore of'the gear 12-7, andsubstantially free therewith. The gear 127 is provided with clutch-teethadapted to engage with clutchteeth 129 formed on the clutch-collar131.). spliued upon the sleeve 131. Said sleeve 131 is provided tosecure free and easy movement in the shifting actions ot thec-lutclncollar 130 and it also con orms to better practice, than bysliding the collar 130 directly upon the screw. When the clutch collar130 is thrown to the left into engagementwith the gear 127, the screw isin driving connection with the shaft 86 for revolving the screw.

It is desirable to lock either the screwshaft or nut against rotationwhile one or the other is rotating", and this is accomplished as follows:Upon the opposite face of the clutch-collar 130,- are providedclutch-teeth 132 adapted to engage with teeth 133 formed in the bearingsleeve 109 which is held against rotation, or fixed within the bearingsot the frame B. As the clutch-member 130 is keyed indirectly through thesleeve 131 to the screw-shaft 76, it will be seen that when the teeth ofthe clutch-collar 130 are engaged with the teeth of the bearing-sleeve109, the screw 76 will be locked against rotation, and that suchposition of the collar is opposite from its en gagement withthe gear 127when in driving connection, whereby it is impossible to lock. the screwagainst rotation, and at the same time maintain it in drivingconnection.

The nut locked by provioing the sleeve 11% with a pin 134:projectingtherefrom, and adapted to engage with airarm 135 pro3ectingfrom the clutch-shitting lever 136 moving in the path'ot' rotation ofthe pin when the lever' is swung to a position disengag ing the clutch111 from the sleeve "114*. This construction likewise prevents thesleeve 111 from being simultaneously locked and enageu tothe drivingshaft 86.

.The operation of positively locking the screw and nut. whenever theyare idle, while.

not essential in certain instances when the parts are quite free to moverelatively to one another (sincethe one will not have arotative'tendency upon the other) but in other instances, the parts maybecome slightly bound, and this would cause the one to rotate the'o'therin such a way as to and injure the work. Therefore, as a pro cautionarymeasure, a locking means is provided." It is obvious that theconstruction h'erein'illustrated can he variously-modified,

bring; the work to the cutter,

disturb the feed.

,ario

Under the'control of clutch members 111 and 130, the various forward andre verse feeds are obtained. .1 y providing means for shifting theseclutches under the actuation of the carriage or 'ieethmeinher, the feedscan be automatically controlled. A variety of results is made possible,by this arrangement, by determining the man.- er of shifting the twoclutches. By this mechanism, the travel oi? the carriage can be governedor controlled so as to be fed to the work very fast, until it reaches apoint where tle cutting is to commence; whereupon, the nut is o hedriven and; the screw is to remain at rest. By throwing the shaftinto criving connection with. both screw and nut, a slow forward feed isproduced and maintained throughout the cuttinooperation. Thereafter; thescrew will again he disengaged, and the nut will remain opentivelyconnected with the propelling ele ments, and this results in a f stforward feed, and is in turn followed by a second slow for ardteed'thereinaon, when the nut is disengaged, a return. travel of thecarriage is produced, and then by disengaging the screw, the carriagewill be automatically brought to rest in its initial starting posh tion.I

During the movements at the carriage just descrihed, .two ditierentlypositioned pieces of work, one in znlvance of the other, were subjectedto the action of the cutter. Of course, this number can be multiplied,to any extent, depcndian upon the length of travel ot the carriage andthe size of the work. Again, should but one piece 01'' worlr hesupported noon the table, the carriage could he given a forwardquick-traverse, to and then-it could feed during the cutting action;after which the carriage could be stopped or returned to normal. avariety of such results is possible, dependinglargely upon the kind ofwork ma'coined.

The following mechanism is provided for automatically controlling theclutch me1nher 111:-i lever 136 s suitably pivoted within the frame 142;one end engaging with the annular groove of the clutch member 111. andthe optiosite end engaging with a forked plate 1&0 fixed upon the rockshaft 141, which projects vertically and is jour naled within a hearingformed in the supplenient-al-casingz 142- tixed to the maincasing E. anarm 143 is fixed upon the rock-shaft 141 and adapted to be en raged by adog .or dogs projecting from the carriage to rock the shaft 111, andshift the lever 136 in the desired direction either to engage ordisengage the'clutch member 111 with the sleeve 114;, tor controllingthe rotation of the nut. 1

To insure a shifting of the clutch, means are provided for automaticallyrocking the shaft 141 after a given positive movement thereof. Atoothed-disk 144; is fixed to the rock shaft 141. 'A toothed detent pin145 is slidably mounted within the frame 142, andurged outwardly bymeans of the spring 146, and there held against rotation by. means of aset-screw 147 threaded within the frame 142 and engaging into a grooveformed in the detent pin 145. Thus, in rocking the shaft 141, say towardthe left, the detent will ride upon the tooth 148 (see Fig. 10) of thedisk 144, until the apexes thereof engage with each other and bring theapex of the detent pin 145 upon the opposite angle of the tooth, atwhich position the tripping-dog of the carriage has moved the rock-shaftand clutch to a point where the clutch has just disengaged from itsopposing clutch member, whence the tension of spring 146 will be exertedand move the clutch-member the remainder movement required. Owingto theclutch member being released from its driving connection with the drivenmember, very little power is required to throw the clutch. This is alsotrue when the clutch is shifted in the opposite direction after theclutch teeth have initially been engaged.

The rearward portion of the arm 143 is provided with a handle 149,whereby the clutch 111 can be manually controlled.

The clutch-member 130 has similar meclr anism to that described for theclutch-meniher 111, to control the same. and comprised of the followinginstrumentalities:

A. lever 150 is pivoted upon the same axis as lever 136, with one onethereof engaged within the annular groove formed within the clutchmember 130. The opposite end is engaged with a forked plate 151 which isfixed to a rocleshaft 152, but the connection between lever 150 and theforked-plate is such as to provide idle or lost motion between themembers/in order to insure the proper movement of the clutch-member 130,for the reason that it engages clutch teeth at the limits of bothmovements thereof, right and left. The rock-shaft 152 isprovided with atoothed-disk 154 like that of the rock-shaft 14 1. A spring controlledde tent-pin T is engaged with the tooth or teeth of the disk andperforms the same functions and operations I have described for similarmechanism of clutch 111.

As illustrated in the drawings, three sets of tripping dogs areprovided; one for tripping the clutch-member 111; the second forengaging the pin 15? for shifting the arm 158 in one direction; and thethird for engaging the pin 158 to shift the arm or lever 156 in anopposite direction. carriage is provided with two longitudinal groovesor T-ways 160 and 161 to receive the clamping bolts of the respectivetrip ping dogs 162, 163 and 164, arranged at predetermined points forautomatically controlling the carriage travel or feed. The trip dog 162(of the first series) engages the arm 143 to actuate the clutchnncndmr111.

to control the nut. The trip dog 163 ongages the pin 158 of the lever156' to throw the clutch-member130 to the left to bring it into drivingrelation with the screw. The trip dog 164 (of another series) engagesthe pin 157 and throws the clutch 12-50 in an opposite direction; thuslocking the screw against rotation.

The trip dogs 164 can be arranged to swing, when a number of them areemployed, so as to move out of position during a return travel of thecarriage, when the stops are arranged to return the carriage upon thecompletion of the working movements of the carriage.

It is obvious that, while these dogs are shown arranged in differentlongitudinal planes, and. each are shown provided with a laterallyprojecting cam-surface adapted to engage the trippingpart of therespective clutches, the construction of the dogs can be variouslymodified and positioned upon The table or p the carriage, otherwise thanherein shown I but within the scope of the claims.

Several diagrammatic arrangements are also illustrated for yielding twodifferent ways of controlling the carriage travel, and

will promote a clear understanding of the operation of the automatictrip mechanism. With the carriage traveling in the direction shown bythe arrow, Fig. 12, a represents the first position of the clutches,bjoth being disengaged'and the, carriage being at rest. By

shifting the handle 149 to the right by hand,

the clutch-member 111 will be engaged with the sleeve 114, therebydriving the nut. This position enables the clutch-member 130 to becomeengaged with the lock-sleeve 109, thereby locking the screw againstrotation and' producing a fast forward speed, the members beinginpositionas shown at 'b. After the carriage has moved a predetermineddistance toward the work, the pin 158 engages a tripping dog 163, whichwill throw the clutch-member 130 into eng'agement with the gear 127,thereby producing a slow forward feed. The various elements will occupythe positionlshown at c in Fig.

12, so as to feed the carriage slowly during tion.

l or cutting tool.

gage .the arm 1&3, so as to disengage'the clntclrmeniber 111 which stillremains in driving relation with the screw-shaft. The various shiftingelements now' occupy the .position shown at 7, which produces a quickreturn. At the end of the return stroke, a trip dog 165 is enabled todisengage the driving capacity of the screw and bringing the carriage torest.

In Fig. 13, a shows the parts in idle posi- 6 illustrates the clutchmembers when they have been shifted for producing a fast forward "feed;which shitting is done manually. The position of the clutch 130 toproduce a slow-forward feed, is shown by 0 The position of the clutchfor yielding a fast forward feed is shown by (Z the clutch 130 beingdisengaged. The position of the clutch 111 which brings the carriage isshown by 6.

tem of carriage-control is one in'which itis necessary to remove thework, or adjust the cutter so asnot to engage to enable the carriage tobe antomaticallyreturned to normal, without 111]11Zy to the work Toprevent the screw shaft from being locked against rotation. whilethelnutis at rest for a hand-feed, I provide the following mechanism or means IThe lever 136 for shifting the clutch, 111, is provided with aprojecting lug 166 adapt; ed to engage with a boss lol'projecjtedtrom ys v one side of the lever 1.00, provided fOlLSllll'lling the clutchmember 130, whereby it .will

be seen that it will be impossible to throw clutch member 130 into itsscrew shaft lock ing positioinwhile the nut is at rest. As will beclearly seen from Fig. 1. the twolevers willengage witheach other, bybringing the boss and lug of the respective levers into abutment.-Should either of them be moved toward the other, the nut would be throwninto driving connection, thereby producing apower feed, and before thesame could be 1 fed manually,it would be necessary to move theclutch-shifting lever of the clutch 130 to aposltionto d sengage thesame from its screw-shaft locking position.

A dog 162' The position given manually to the clutch 130 to produce a quck the work on the return stroke; while in the system of Fig. 12,] thework and cutters are oi such nature. as.

This forms a safety" means for locking the screw-shaft against rotation,when it is desired to rotate the same by hand.

Continuing by way ot an analysis of my improvements in cohnection withthe above disclosed construction, it may be observed that my arrangementisfishown applied to a table preferably actuated automatically in anydesired man ed; Thus, referring, more especially to Figs. lt lo and 1.6,D indicates a main-table,adapted torec iprocate on a suit ablesupporting-element A which may be the bed of the'machine, orwhich may bea so-called saddle knee or'other corre spending element. This tableslides on the bearing surfaces 1' and 2' and is positioned by means ofthe slid the Ordinary mannenas will be understood. So also, the table Dwil l by means of suitable propelling mechanism, su'ch"as'that abovedescribed be caused reciprocate or travel back and torthat. an desiredrate, as, for example,

at a feed? rate during the going stroke and ataFciuick-traVeise duringthe return stroke. 1

The upper dicated by D and may be regarded either as a part of the tableO or as an auxiliary D supported thereby; Inthis instance, the aux.-

iliary table provided with arock shaft 5 passing through lug portions6', 7' and 8 and secured at one end by a head 9' and at the other end bya nut 10 so that it will 'con-' stitutea pivot I licit very accuratelyand snugly seated in the auxiliary table D. This bolt alsopassesthroughaccurately fitting aperturesdn lu' s 11" and 12 extendingfromthetable l5 and located near one end thereof asshownby'l ig. 14.

l'kt a considerable distance from the pivot bolt 5' areflmonn'ted wovertical hardened pins 18 which are snugly seated in sockets 1ft andwhiclr preferably may be adjusted vertically by me'an's of thescrews15"; The lower ends of these pins'pajss loosely through wells 16'' inthe table I), and rest upon either tlileinfdper steps 1'7 zor the lowersteps 18' of a'r 'shittable member HI 'The'upper steps 17 maintain theauxiliary'table D in its normal work-tooling position, and thelowerstep" 1Spermits theetable to tilt or drop sufiiriently for the cutter'toclear the work-dun ing thereturn stroke. In order that the table maybevery rigidlyheld in its normal posis tionand to pro-vent itfrom risingup under the cutter action, astop element, such as the sc'rewlt)", maybe provided". This screw is threaded at 20 to the auxiliary table andits shank passes through a well in the table D so that its head 21 maybear against the shoulder of the well and limit the upward movement ofthe anxiliary'tablej By adjusting the screws 13 and 19 when the partsare shown in the position shown by Fig. 16

portion o tl this table, is here in i it is evident that the uppersurface of the table may be brought into a position absolutely parallelwith the bearing surfaces 1 and 2.

'The mechanism for automatically shifting element H so as toautomatically raise and lower the auxiliary table at appropriateintervals simply consists of a dog L to lower the table and a dog R toraise or restore'the table to its normal position. These dogs, which areadjustably bolted to a 'T-slot 22', cut into the side of the saddle orbed D; the dogs being retained by means of headed bolts 5'3, as shownbest by Fig. 16. The dog L is provided with a contact surface 24' andarranged at an angle and adapted to impact a corresponding contactsurface 25 provided by an extension 26 of the member H so that, as thetable travels toward the end of its stroke, this contact surface 24:will cause the element H to shift to the left, as seen by Fig. 16,thereby bringing the seats 18' into relation with the pins 13. Theelement H is in this instance prevented from rotating by means of asuitable spine 17 Now when the table is at the end of its return stroke,the contact surface 28' will impact a complementary surface 29 providedby the dog R and the element H will be pushed to the right, therebyraising the table into proper position for the next cutting stroke. Itwill be understood that, while the rotary milling cutter has not beenspecifically illustrated, that this invention contemplates the use ofthis table in conjunction with any type of milling cutter mounted on anyconventional spindle mounting, as, for example, in the way shown in anordinary milling machine of the knee and column type, or, as shownforexample, by the above described construction.

lVithout further analysis, the foregoing will so fully reveal the gistof this invention that others can by applying current knowledge readilyadapt it for various applications without omitting certain featuresthat, from. the standpoint of. the prior art, fairly constituteessential characteristics of the generic or specific aspects of thisinvention, and therefore such adaptations should and are intended to becomprehended within the meaning and rangeof equivalency of the followingclaims.

Having thus revealed this invention. I claim as new and desire to securethe following combinations of'steps and elements, orequivalents thereof,by Letters Patent of the United States I 1. The combination of arecipiocatory slidable member, work carrying means on said slidablemember, and means governed by the. movement'of the slidable member, foreffecting the movement of the work relatively to the slidable member atany one of a selection of different points in the travel of saidslidable member.

2. The combination of a reciprocatory slidable member, work carryingmeans on the slidable member, a pair of normally fixed means supportedby the framework, and means actuated by said fixed means at differentselectively available points in the travel of the slidable member forcausing the movement of the work toward and from the slidalile member.

3. The combination of a reciprocatory slidable member, means for guidingsaid slidablc member for movement in a straight path, means forsupporting a tool in ope1'a tive relation to said slidable member,workcarrying means on said slidable member, and means for causing themovement of the work-carrying means toward and from the tool relativelyto the slidable member at a variety of different points in the travel ofsaid slidablelnember.

l. The combination of a reciprocatory slidable member, means forsupporting a cutting tool in operative relation to and above saidslidable member, workwarrying means on said slidable member, andadjustable mechanism for causing the elevation of thework relatively tosaid slidable member and into contact with the tool, maintaining theengaging relation between the work and the tool for a pre-determinedperiod in the advance of the slidable member, and for causing thelowering of the work away from the tool relatively to the slidablemember and at the conclusion of a cut and for maintaining it in loweredcondition for a predetermined period during the retractive movement ofthe slidable member.

5. The combination of a rcciprocatory slidable member, .means forguiding said slidable member for movement in a straight path, means forsupporting a tool in operative relation above the slidable member, andadjustable means for causing the movement of the work upward for actionby the tool and for causing the lowering of the work away from the toolboth relatively to the slidable member at a variety of different pointsin the travel of the latter.

6. The combination of a reciprocatory slidable member. means for guidingsaid slidable member for movement in a straight path, means forsupporting a tool-in operative relation to the slidable member, workcarrying means on the slidable member, and means for causing themovement of the work toward and from the tool relatively to the slidablemember at different selectively available points in the travel thereofand for non-yieldingly supporting the work when it is being acted uponby the tool.'

7. The combination of a reciprocatory slidable member, means forsupporting a cutting tool in operative relation to and above saidsiidable member, work-carrying means on said slidable member, andadjustable mechanism for causing the elevation of the Work relatively tosaid slidable member and into contact with the tool, maintaining theengaging relation between the work and the tool for a predeterminedperiod in the advance of the slidable memher, and :for causing thelowering of the Work away from the tool at the conclusion of a cutrelatively to the slidable member and for maintaining it in loweredcondition for a pre-determined period during the retractive movement ofsaid mechanism comprising means for nonthe slidable member,

yieldingly receiving the thrust of the tool during the cuttingoperation.

8. A reciprocatory member; a Work-support hinged thereon; an elevatingelement 20 carried by said member for lifting said support; and astationary dog adapted to shift said element to elevate said supportabout its hinge.

In Witness whereof, I hereunto subscribe 25 my name, as attested by thetwo subscribing witnesses.

ROBERT T. HAZELTON.

